This invention relates to compositions of the matter comprising alkoxylated dihydrocarbyl dithiophosphoric acid-phosphite derived olefin and polymeric olefin adducts as unique multifunctional additives as well as multifunctional lubricants possessing inherent multifaceted internal synergism. These unique multifunctional additives in minor amounts are also highly useful additives for liquid hydrocarbon fuel compositions.
Lubricants, such as lubricating oils and greases, are subject to deterioration at elevated temperatures or upon prolonged exposure to the elements. Such deterioration is evidenced, in many instances, by an increase in acidity and in viscosity, and when the deterioration is severe enough, it can cause metal parts to corrode. Additionally, severe oxidation can lead to a loss of lubrication properties, and in especially severe cases this may cause complete breakdown of the device being lubricated. Many additives have been tried, however, many of them are only marginally effective except at high concentrations. Improved antioxidants are clearly needed.
Antioxidants or oxidation inhibitors are used to minimize the effects of oil deterioration that occur when hot oil is contacted with air. The degree and rate of oxidation will depend on temperature, air and oil flow rates and, of particular importance, on the presence of metals that may catalytically promote oxidation. Antioxidants generally function by prevention of chain peroxide reaction and/or metal catalyst deactivation. They prevent the formation of acid sludges, darkening of the oil and increases in viscosity due to the formation of polymeric materials.
Water (moisture) is another critical problem. In spite of even extraordinary precautionary efforts water is found as a film or in minute droplets in vessels containing various hydrocarbon distillates. This brings about ideal conditions for corrosion and damage of metal surfaces of the vessels and the materials contained therein. Also in the lubrication of internal combustion engines, for example, quantities of water are often present as a separate phase within the lubricating system. Another serious problem in respect to metallic surfaces in contact with adjacent metallic surfaces is the surface wear caused by the contact of such surfaces. One material capable of simultaneously effectively coping with such problems as these and providing simultaneous multifunctional characteristics, in addition to antioxidation and anticorrosion, such as EP/antiwear, antiwear and extreme pressure and friction modifying characteristics while maintaining fluid lubricity is highly desireous.
U.S. Pat. No. 4,532,057 discloses a lubricant and liquid fuel compositions containing a hydrogen phosphite-vicinal diol reaction product which provides additional protection to metals parts in contact by reducing the amount of friction.
The use of phosphorodithioate compositions, especially the corresponding salts of phosphorodithioate, such as zinc dialkylphosphorodithioates (commonly known as zinc dithiophosphates) have found widespread commercial use for several decades in engine oils as multifunctional antiwear, peroxide decomposing, and bearing corrosion inhibiting additives. U.S. Pat. No. 2,758,971 describes certain metal phosphites as having properties which prevent breakdown of lube oils at high temperatures and U.S. Pat. No. 4,356,097 discloses an engine crankcase oil containing a dihydrocarbyl hydrocarbyl phosphate which exhibits reduced friction.
The general peroxide catalyzed reaction of dialkyl hydrogen phosphites with conventional olefins to give phosphonate derivatives is known as disclosed in U.S. Pat. No. 2,957,931. The use of these materials as multifunctional additives in a variety of lubricant applicant applications is also known.
It is an object of this invention to provide additive reaction products which exhibit excellent lubricating properties in conjunction with good extreme pressure/antiwear, antioxidant and friction reducing properties.